From CBC: The frantic activity that follows the May 31, 1985, Barrie tornado is a whirlwind of its own. The storm is devastating: eight killed, 155 injured, 300 homes destroyed and $100 million in damage. Yet in its wake, local residents are transformed from terrified victims to a unified army bent on rescue, restoring order and providing comfort. Reporter Doug James follows Barrie residents through 48 hours of hell.

Tornado tracks across Central Ontario during the May 31, 1985tornado outbreakDate of tornado outbreak: May 31, 1985Duration1: ~3-5 hours Maximum rated tornado2: F4 tornado Tornadoes caused: 13 confirmed Damages: In 1985 Canadian Dollars: $110 million (adjusted to 2006, CND $250 million) Fatalities: 12, 224 more injured[1]Areas affected: SouthernOntario, Pennsylvania, Ohio, UpstateNew York 1Time from first tornado to last tornado
2Most severe tornado damage; see Fujita Scale
On the warm late spring day of May 31, 1985, one of the largest and most damaging tornado outbreaks in Ontario’s history hit the province. All total, 13 separate tornadoes, with two of them killers (rated at F4 on the Fujita Scale), crossed southern Ontario during the late afternoon and early evening hours that day – several people died, hundreds more were injured, and with many millions of dollars in damage for the province of Ontario alone. One of the tornadoes devastated the city of Barrie, nestled at the far western edge of Kempenfelt Bay, on Lake Simcoe.
Another, equally devastating tornado farther south tore a path over 100 kilometres long, parallel and north of Highway 9, passing through several towns in the process. This unprecedented outbreak was part of a larger one in Ohio, Pennsylvania, and New York. Several of those tornadoes were violent as well. Conditions were perfect for such a major late spring tornado outbreak that May 31st, which later became known as “Black Friday”.Contents

The 500mb pattern was conducive for a major severe weather event in the Great Lakes that Friday, May 31st. An unseasonably deep low pressure system at 984mb crossed out of the Midwestern U.S. through the day, and then into the Upper Peninsula of Michigan. Very warm air surged in ahead of this system. Temperatures reached the upper 20s in Celsius (about 80-85F) across much southern Ontario, in addition to high dew point levels. High instability (minus 6, in terms of surface based lifted indices) was the byproduct of this. Directional wind shear was also present in the warm sector of the storm (in addition to high helicity values and a vorticity maximum approaching the lower lakes).
The situation was worsened by the presence of copious amounts of moisture, which would allow any storms that could form to become severe rather quickly. Also, this was supportive of the HP (high-precipitation) counterpart of the supercell thunderstorm. All of this added up to the distinct possibility of severe rotating storms that were messy, hard to see, and extremely dangerous. What was needed now was a trigger, and that came in the form of a trailing cold front behind the low. Thunderstorms and isolated tornadoes had already raked parts of the Midwest U.S. the day before, on the May 30th with this same cold front.
The day started off on an active note with the warm front moving northwards. A weak (rated F0) tornado was reported near Leamington, accompanied by large hail from widespread severe thunderstorm activity in southwestern Ontario. Following the warm frontal passage, skies cleared rapidly and temperatures quickly began to rise. The cold front began crossing Lake Huron towards the noon hour, and with it several thunderstorms developed shortly after 1:30pm EDT, with the northernmost cell soon becoming most dominant. Environment Canada issued a severe thunderstorm warning at 2:25pm for Bruce County (complementing the special weather statement issued early that morning). At around 2:50pm, a tornado (later rated at F2) touched down briefly in the Lion's Head area, north of Wiarton.

The Northern Supercell

At about the same time the Lion's Head tornado dissipated, two very severe thunderstorms had developed (that probably owe their inception, at least partially, to lake breeze convergence): one to the east of Clinton and another farther to the north, in the Walkerton area. These two developing supercells would grow into a pair of incredibly devastating, monster storms within the next hour - likely the most prolific tornado producers in Canadian history to date.
Satellite image as the tornado was entering Barrie

The second tornado of the day touched down south of Hopeville, causing some localized F3 damage along its track. The tornado lifted after a 17 kilometre path, but another tornado quickly formed just north of Corbetton, in northern Dufferin County at about 4:15pm. It stayed over rural areas for most of its 40 kilometre path, however a few homes (especially in the Terra Nova and Mansfield area) sustained F3 damage (it has been somewhat disputed whether this path was of two separate tornadoes, rather than just one). In any case, shortly after this tornado had clearly dissipated, there were hints of another brief touchdown near Angus (north of Alliston). This northern storm (clearly a cyclic supercell) was far from finished. The next tornado was the last of this storm, but was the most infamous one. It formed in southern Simcoe County, less than 10km southwest of Highway 400 and the Barrie city limits.
Tornado damage in Barrie

Shortly after 4:30pm, all electrical power in Barrie went out, as the tornado took out the main hydro transformers, southwest of the city. Few residents had any idea of what was looming over the horizon, but many people were let off work 30 minutes before the storm hit due to these power outages. Had this not happened, the death toll would have undoubtedly been much higher.[citation needed] The intensifying tornado first obliterated a pine tree forest plantation. Some 10 metre high trees were snapped at the 2 metre level. At this point the damage path was about 600 metres wide, moving steadily towards the east-northeast. It then entered the southern part of Barrie shortly before 5:00pm. Visibility was very low as the tornado was cloaked in heavy rain and dust, thus making it very difficult to see. Extensive F3 (although some localized F4) damage occurred to an entire square block of homes in the Crawford Street and Patterson Road subdivision. Three people were killed in the area as many homes there were not well-built, and thus easily collapsed after being pushed off their foundations.[citation needed] Most of the fatalities occurred in homes with no basements.
Next, the tornado hit an industrial complex. One person died there while at least 16 factories were damaged or destroyed. Steel I-beams were twisted horribly out of shape, and splinters of wood were found in nearby concrete walls. The tornado then proceeded to cross Highway 400 at Essa Road (former Highway 27) interchange, just missing the Barrie Racetrack to the south. The grandstand was heavily damaged and several barns nearby were destroyed. Many nearby vehicles were picked up off of Highway 400 and then deposited into the ditch, remarkably again with only some injuries and very close calls. Highway guard rails were found wrapped around telephone poles nearby. Many cars were also found with puncture holes in their frames, owing to flying debris. As it crossed the highway, it moved into the Hillsdale subdivision.
Many homes sustained severe damage there, with much of their upper floors missing. By this time the tornado’s path had narrowed to about 300 metres. The track moved from Debra Crescent to Joanne Crescent with more extensive damage. Near Tower Crescent, the path narrowed to a comparatively small 50 metres. On Briar Road, homes sustained only minor damage, indicating that the tornado had weakened somewhat. But the next road east, Trillium Crescent had sustained heavy damage indicating that it had strengthened once again. Four warehouses near Highway 11 were ripped apart. It then hit the Tollendal Woods and Minets Point area (four more people died here), taking out a marina and a nearby subdivision. Close to 40 boats and their concrete moorings were tossed into Lake Simcoe and were never recovered. The tornado then moved out over Kempenfelt Bay where it became a waterspout for a brief time before weakening out completely. It came very close to the opposite shore, but no damage was reported there. Eight died in Barrie, 155 were injured,[2] and many homes were damaged or destroyed.

The Southern Supercell

Shortly after 4:15pm, the storm which had initially developed east of Clinton produced a new tornado a couple kilometres north of Arthur. Many power lines and hydro towers were destroyed along the path, but it was mostly over rural areas. The tornado quickly widened, intensified and reached violent proportions when it reached the small crossroads community of Grand Valley just before 4:30pm (the damage path was approximately 200 metres wide at that time). The tornado caused major damage in the small village and killed another two people (one in a home, the other in a pickup truck). The worst damage was along Amaranth Street, where the local library, two churches, and many other homes were severely damaged or destroyed. About 40 structures in total sustained damage, the most severe was on the north side of the street, where some homes had classic F4 damage. The tornado then continued eastward through more open country, brushing the northern outskirts of Orangeville where the southern portion of the Mono Shopping Plaza completely collapsed, seriously injuring one person.
The tornado then caused extensive damage to approximately 20 buildings (many of which were only recently built) about two kilometres south of the town of Tottenham at around 5:00pm. Two people died (one in a home, and the other in a frail shed). The tornado kept moving east-northeast, crossing Highway 400 into York region. It just missed the cities of Newmarket and Bradford before lifting west of Mount Albert at 5:25pm, with a path length in excess of 100 kilometres (thus becoming a Canadian record that still stands today). When the earliest tornado track maps were published within the next year, they showed this particular tornado to have tracked almost twice as far towards the Peterborough area before dissipating. In more recent years this has proved to be incorrect.

Most of the tornadic activity at this point moved into southeastern Ontario producing more tornadoes (some significant). These tornadoes formed around the Highway 7 corridor from Lindsay to Madoc (mainly between 6:00 to 6:30pm), near the towns of Wagner Lake (F1), Reaboro (F1), Ida (F2), Rice Lake (F3). Most of these tornadoes had conversely shorter paths than the earlier tornadoes, due to the supercells beginning to weaken. In addition, they did not receive as much media attention as the previous tornadoes (those earlier storms were grouped collectively by the media as comprising “The Barrie Tornado”), probably because they didn’t have the opportunity to cause as much damage.
Even so, at the time these more eastern tornadoes were touching down, a final, more isolated supercell developed near the Milverton in eastern Perth County, that produced a tornado at 6:15pm tracking a 33 kilometre path of sporadic F3 damage (mainly to outbuildings) from Alma east-northeast towards the Hillsburgh area. Its path was almost parallel to the Grand Valley/Tottenham tornado only a couple of hours earlier.
Meanwhile, lines of severe thunderstorms rapidly developed south of Lake Erie in Ohio and Pennsylvania in the United States, along the cold front itself. Swarms of tornadoes began touching down after 5:00pm in the northwest part of that state. Some of the hardest hit were towns such as Atlantic, Albion, Bradford, and Cooperstown. Later in the evening, some of these tornadoes crossed into New York, affecting southern Chautauqua and Cattaraugus counties the worst (as these supercells moved northeast across Lake Erie into Ontario after 7:00pm, they produced baseball size hail near Niagara-On-The-Lake, with extensive hail damage).

Aftermath

Following the event twelve people were dead, 155 were injured[3], hundreds more were left homeless and out of work as close to a thousand businesses and homes were wiped out. Houses were reduced to huge piles of debris and rubble. In the hours following the event, soldiers from Canadian Forces Base in Borden (CFB Borden, which barely escaped the tornadoes themselves, the twister having momentarily touched down in the Blackdown Park Training Area on Base before lifting off again and passing over the built up area of the Base proper, missing hundreds of married quarters) assembled in Barrie to assist in the canvassing of the worst affected areas of the city. In addition, wooden pallets were donated by a local trucking company in Barrie so survivors could salvage their possessions and the (former) Grand Valley library donated books.
Most of Grand Valley was completely rebuilt by August 1986, a little over a year later. Even to this day there are still hints from the past of the tornadoes that day. Some of the wooded areas that were affected in Ontario are still a twisted mess, and some random debris still remains scattered in the bush to the east of Highway 400 in Barrie. In the end, the price tag for the tornadoes in Ontario alone topped $110 million (in unadjusted Canadian dollars, 1985). This would correlate to nearly $250 million in Canadian dollars by today’s standard, a very expensive weather disaster indeed.